Expression of the potassium channel KV3.4 in mouse skeletal muscle parallels fiber type maturation and depends on excitation pattern.
We report the detailed expression pattern of the voltage-dependent potassium channel KV3.4 (rat homologue, Raw3) in mouse skeletal muscle. Using semi-quantitative RT-PCR, we show that its expression is detectable at embryonic day 17 and rises to adult levels within 2 weeks after birth. Expression is fiber type-dependent, with mRNA levels being 5-6-fold lower in the mixed slow/fast soleus muscle than in the fast tibialis anterior and extensor digitorum longus muscles. Fast muscles from myotonic mice exhibit low KV3.4 mRNA levels similar to those of wild-type soleus. In denervated extensor digitorum longus, KV3.4 expression declines to perinatal levels. We conclude that KV3.4 expression in mouse skeletal muscle is regulated by the pattern of excitation.
Vullhorst
D
D
Developmental Biology Unit, University of Bielefeld, Germany.
Klocke
R
R
Bartsch
J W
JW
Jockusch
H
H
D000818:Animals; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009121:Muscle Denervation; D024510:Muscle Development; D018485:Muscle Fibers, Skeletal / Q000378:metabolism; D018482:Muscle, Skeletal / Q000254:growth & development / Q000294:innervation / Q000378:metabolism*; D009222:Myotonia / Q000378:metabolism; D015221:Potassium Channels / Q000096:biosynthesis* / Q000235:genetics
D015221:Potassium Channels